This study is designed to determine whether parent training is an effective means of increasing children~s consumption of a high calcium diet and increase their strength and aerobic exercise in order to prevent osteoporosis as adults. Sedentary children (N = 180) with a history of low calcium intake and a family history of osteoporosis will be recruited sequentially. Males and females form different racial/ ethnic backgrounds will be included. One child/family will see as the unit of random assignment A 2 X 2 X 7 random assignment, repeated measures, design will be employed. Children and their parents will be divided into two groups. The experimental group will receive educational and support services for diet and exercise change in the target child (N = 90) . Each of these conditions will be divided again at random into two subgroups: one ( N = 45) will obtain parent-training concerning the target topic (i.e. Safety or diet and exercise); the second group (N=45) will obtain the same instruction plus episodic coaching. Training will require 12 weekly classes and will emphasize principle of behavior and contingency management techniques. Coaching procedures will be provided over 9 months and will assist parents with problem-solving in order to refine and maintain parenting skills. Measures will be obtained seven times, prior to parent-training, at the end of parent training ( at 3 months) , and repeatedly through the coaching and one year follow up period. Outcome measures will include 24 hour recall estimates of change in diet., and change in physical activity. These will be validated by objective outcome measures, including 5Rm strength and , VO2 max fitness measures. Using stat of the art DXA scans, total bone calcium, bone density and specific site bone density will be obtained. Body composition and skeletal age also will be assessed by DXA Generalized estimating equations will be employed to estimate main effects covariates, and interactions to test study hypothesis. Exploratory analyses will include assessment of hypothetical processes, such as parenting practices and child/parent interactions (based on objective video tape measures as mediating variables in achieving changes in bone density . Results will inform clinical and educational prevention of osteoporosis in male and female from different racial/ethnic backgrounds at risk of osteoporosis as adults.